Field of the Invention
The present invention relates to a timing controller, a display panel, and an organic light emitting display device, and a driving method thereof.
Discussion of Related Art
Recently in the spotlight as a flat panel display device is an organic light emitting display device. Such a device adopts an organic light emitting diode that illuminates light by itself, and thus has advantages of a fast response time, high illumination efficiency, a wide illuminating and viewing angle, and the like.
In such organic light emitting display devices, sub-pixels including the organic light emitting diode are arranged in the form of a matrix, and brightness of each of the sub-pixels, selected based on a scan signal, is controlled depending on gradation of data.
Each sub-pixel includes circuit elements such as an organic light emitting diode and a driving transistor for driving the organic light emitting diode. The circuit elements included in each sub-pixel have characteristic feature values. For example, the driving transistor has a characteristic threshold voltage and a characteristic mobility. The organic light emitting diode has a characteristic threshold voltage.
The feature values of each circuit element may change due to deterioration, depending on a driving time. Further, changes in the feature values of each circuit element may be different from the changes in the feature values of circuit elements in other sub-pixels.
Such changes of the feature values of each circuit element and variation of the feature values between the circuit elements causes luminance variation between sub-pixels, which generates non-uniformity of the display panel's luminance. Thus, image quality can be decreased.
Therefore, compensation technologies for reducing variation of the feature value between the circuit elements by sensing the feature value or variation of the feature value of the circuit elements have been developed. However, there is a problem that the variation of the feature values of the circuit elements cannot be compensated due to imprecise sensing or false sensing of the feature values, or the variation of the feature values, of the circuit element.
For example, when humidity is increased over a predetermined level in the organic light emitting display device, a phenomenon exists that a signal line, an electrode, or the like, of a display panel may short circuit. In this case, a problem that the variation of the feature value of the circuit elements cannot be compensated due to imprecise or false sensing of the feature value, or the variation of the feature value, of the circuit element may occur, which causes an abnormal display phenomenon.
In an excessive case, a phenomenon of overcurrent in the display panel or a burnt display panel may appear.